This invention relates to a small (i.e., compact) gas turbofan engine and, more particularly, to such an engine which has a high bypass ratio and a regenerator.
With the advent of cruise missiles, small gas turbofan engines have been necessary. Although the conventional gas turbofan aircraft engine may vary from ten to twenty feet in axial length and from three to eight feet in diameter, a cruise missile gas turbofan engine should not exceed approximately two feet in axial length and approximately one foot in diameter. To those not skilled in the art, the obvious answer to attaining such a small gas turbofan engine would appear to miniaturize the components. Regretably, as is well known in the art, miniaturization of components is not the solution, because of cogent technological reasons, including the great difficulty in getting the low pressure shaft (of the turbine that is connected to the fan) through the center of the high pressure "spool" (i.e., the compressor, the burner, and the high pressure turbine). Additionally, with small gas turbofan engines, the prime requirement (other than size) is good fuel consumption during part-power (as distinguished from fuel-power) operation.
I have invented a unique small gas turbofan engine which not only meets size requirements, but also substantially reduces fuel consumption during part-power operation because of its high bypass ratio and its regenerator.
By this invention, I have significantly advanced the state-of-the-art.